The French Panthéon has shown, both in ancient and recent times, several fractures in the stones of its masonry, which also caused the partial closure to the public visits in the latest decades ...because of the fall of stone fragments. The French Ministry of Culture and Communication commissioned a new study Blasi C. Mémoire sur la stabilité et les lézardes du Panthéon Français, Ministère de la Culture et de la Communication – Service National des Travaux, Direction du Patrimoine, Paris, 2005 to identify the causes of the present disorders, whose results are presented in this paper. A multidisciplinary approach, with a balanced fusion of historical analysis, precision surveys, experimental inspections and numerical modelling, enabled to spot the damage mechanisms that have provoked the first disorders and the ones that are still active, giving hints on the possible solutions. The interest in these studies also arouses from the fact that the French Panthéon, designed in the XVIII century with slender structures and innovative techniques, can be considered as the first building for which tests on materials and “modern” structural calculations have been carried out in a systematic manner. The present studies can thus be seen as the prosecution of a structural inspection that started 250
years ago and is still ongoing.
A global protocol for the thermostatistical analysis of hot nuclear sources is discussed. Within our method of minimization of variances we show that the abnormal kinetic energy fluctuation signal ...recently reported in different experimental data from the MULTICS and INDRA collaborations is a genuine signal of a first-order phase transition in a finite system.
The distribution of fragments produced in events involving the multifragmentation of excited sources is studied for peripheral Au + Au reactions at 35
A MeV.
The Quasi-Projectile has been ...reconstructed from its de-excitation products. An isotropic emission in its rest frame has been observed, indicating that an equilibrated system has been formed. The excitation energy of the Quasi-Projectile has been determined via calorimetry.
A new event by event effective thermometer is proposed based on the energy balance. A peak in the energy fluctuations is observed related to the heat capacity suggesting that the system undergoes a liquid-gas type phase transition at an excitation energy ∼ 5
A MeV and a temperature 4–6 MeV, dependent on the freeze-out hypothesis. By analyzing different regions of the Campiplot, the events associated with the liquid and gas phases as well as the critical region are thermodynamically characterized.
The critical exponents, τ, β, γ, extracted from the high moments of the charge distribution are consistent with a liquid-gas type phase transition.
Using the ALADIN forward-spectrometer at SIS we have studied multi-fragment decays of
197Au projectiles after collisions with C, Al, Cu and Pb targets at a bombarding energy of
E
A
= 600
MeV
. The ...new data presented in this work comprise the measured cross sections of multifragment processes, the
N
Z
ratios of the produced fragments, and the differential distributions of fragment multiplicities and of observables built on the charge correlations within the event.
The
197Au+Cu data are analyzed with the statistical multifragmentation model. It is shown that all observables can be simultaneously reproduced on an absolute scale, apart from an overall normalization constant which relates the number of model events to the measured cross section. A continuous distribution of excited residual nuclei, used as input for the calculations, was derived from the criterion of a best fit to the data. It exhibits a correlation between decreasing mass number
A and increasing excitation energy
E
x
A
and a saturation of the excitation energy at
E
x
A
≈ 8
MeV
.
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